从 Firebase 存储 + ContentResolver 下载（API >= 29）

Question

我正在尝试连接 ContentResolver 和 Firebase 存储下载。

目标：将文件从 Firebase 存储下载到图片库或音频文件夹。

我做了什么：

ContentValues  values = new ContentValues();
values.put(MediaStore.MediaColumns.DISPLAY_NAME, "FileName1");
values.put(MediaStore.MediaColumns.MIME_TYPE, "image/jpeg");
values.put(MediaStore.MediaColumns.RELATIVE_PATH, "Pictures" + customDir);

AsyncQueryHandler asyncQueryHandler1 = new AsyncQueryHandler(myContentResolver){
    @Override
    protected void onInsertComplete(int token, Object cookie, Uri uri) {
        super.onInsertComplete(token, cookie, uri);
        File localFile = new File(uri.getPath());
        StorageReference ref = FirebaseStorage.getInstance().getReference(myFireStorageFilePath());
        ref.getFile(localFile).addOnSuccessListener(new OnSuccessListener<FileDownloadTask.TaskSnapshot>() {
    ........
}
};
asyncQueryHandler1.startInsert(-1, null, MediaStore.Images.Media.EXTERNAL_CONTENT_URI, values);

但是，我得到了错误（即使我请求了权限）：

E/StorageException: Permission denied
java.io.IOException: Permission denied
    at java.io.UnixFileSystem.createFileExclusively0(Native Method)
    at java.io.UnixFileSystem.createFileExclusively(UnixFileSystem.java:317)
    at java.io.File.createNewFile(File.java:1008)
    at com.google.firebase.storage.FileDownloadTask.processResponse(com.google.firebase:firebase-storage@@17.0.0:138)
    at com.google.firebase.storage.FileDownloadTask.run(com.google.firebase:firebase-storage@@17.0.0:229)
    at com.google.firebase.storage.StorageTask.lambda$getRunnable$7(com.google.firebase:firebase-storage@@17.0.0:1106)
    at com.google.firebase.storage.StorageTask$$Lambda$10.run(Unknown Source:2)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1167)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:641)
    at java.lang.Thread.run(Thread.java:919)

我不明白我做错了什么。我可以创建 Uri 然后创建文件吗？

谢谢

Answer 1

最终我无法在 API >= 29 中将 Uri 和 File 结合在一起，但这对我有用：

if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {
                values = new ContentValues();
                values.put(MediaStore.MediaColumns.DISPLAY_NAME, af.getFileName());
                values.put(MediaStore.MediaColumns.MIME_TYPE, "image/jpeg");
                values.put(MediaStore.MediaColumns.RELATIVE_PATH, "Pictures" + customDir);
                values.put(MediaStore.MediaColumns.IS_PENDING, 1);
                AsyncQueryHandler asyncQueryHandler1 = new AsyncQueryHandler(cr){
                    @Override
                    protected void onInsertComplete(int token, Object cookie, Uri uri) {
                        super.onInsertComplete(token, cookie, uri);
                        onUriCreated(uri, af, token, fr);
                    }
                };
                asyncQueryHandler1.startInsert(i, null, MediaStore.Images.Media.EXTERNAL_CONTENT_URI, values);
            }

功能：

    void onUriCreated(Uri uri, Attachedfile af, int finalI, FileRepo fr) {
            if(uri != null){
                StorageReference ref = FirebaseStorage.getInstance().getReference(myFireStorageFilePath);

                ref.getDownloadUrl().addOnSuccessListener(new OnSuccessListener<Uri>() {

                    @Override
                    public void onSuccess(Uri downloadUri) {
                        RetrieveAndInsert(downloadUri.toString(), uri, finalI, af, fr);
                    }
                }).addOnFailureListener(new OnFailureListener() {
                    @Override
                    public void onFailure(@NonNull Exception exception) {
                        // Handle any errors
                    }
                });
             }
        }

这是保存文件的位置：

public void RetrieveAndInsert (String downloadUri, Uri localUri) {
    new RetrieveTask(localUri).execute(downloadUri);
}
class RetrieveTask extends AsyncTask<String, Void, Void> {

    String downloadUri;
    Uri localUri;

    RetrieveTask(Uri localUri) {
        this.localUri = localUri;
    }
    @Override
    protected Void doInBackground(final String... downloadUri) {

        this.downloadUri = downloadUri[0];
        InputStream inp = null;
        OutputStream output = null;
        try{
            URL url = new URL(this.downloadUri);
            URLConnection urlCon = url.openConnection();
            HttpURLConnection httpCon = (HttpURLConnection) urlCon;
            httpCon.connect();
            output = cr.openOutputStream(localUri);
            int lengthOfFile = httpCon.getContentLength();
            inp = new BufferedInputStream(url.openStream(), 8192);// httpCon.getInputStream();

            byte[] buffer = new byte[1024];
            int bytesRead;
            long total = 0;
            while ((bytesRead = inp.read(buffer)) != -1) {
                total += bytesRead;
                output.write(buffer, 0, bytesRead);
            }
            downloadedFiles[0]++;
        } catch (MalformedURLException e) {
            e.printStackTrace();
            cr.delete(localUri, null, null);
        } catch (IOException e) {
            e.printStackTrace();
            cr.delete(localUri, null, null);
        } finally{
            try {
                inp.close();
                output.flush();
                output.close();
            } catch (IOException e) {
                e.printStackTrace();
            } catch (Exception e){
                e.printStackTrace();
            }

            ContentValues values = new ContentValues();
            values.put(MediaStore.MediaColumns.IS_PENDING, 0);
            cr.update(localUri, values, null, null);
        }

        return null;
    }

    @Override
    protected void onPostExecute(Void result) {
        //
    }
}